|Fig. 1 Aerial view of PMA (courtesy of Borrego Solar)
|Fig. 2 The polygon tool for drawing land parcels
|Fig. 3 The Automatic Layout Wizard for solar rack arrays
|Fig. 4 The result of the Automatic Layout Wizard
|Fig. 5 Heat map representations of output in four seasons.
|Fig. 6 Annual yield vs. tilt angle
|Fig. 7 Monthly yields vs. tilt angle
After the layout is done, you can always revise the field. You can drag any rack to resize or move it, delete it, copy and paste it, or add a new rack. The Automatic Layout Wizard is not the only way to add solar panel arrays. It is just a super fast way to add thousands of solar panels at once -- without the wizard, it would have been too time-consuming to manually add solar panel racks one by one. The solar panel field is always editable after a layout is applied.
Let's now check how close our model is to reality. The total number of solar panels of our model is 21,064 -- only 67 more than that of the real PMA solar farm (I had no information about the exact types of solar panels deployed in PMA, so I guessed and selected two different sizes 0.99m x 1.65m and 0.99m x 1.96m for different subfields).
In terms of the annual output, Energy3D predicts approximately 9.6 GWh, about 12% higher than the estimated output of 8.5 GWh by Borrego Solar. I currently do not have access to the real operational data, though.
Having created a computer model allows us to experiment with it to study how to optimize the design. For example, we can easily change the tilt angles of the arrays and investigate how the annual yield is affected. Figure 6 shows that a tilt angle close to the latitude (42 degrees) seems to result in the highest overall annual output.
But the total annual output is not necessarily the only criterion. Sometimes, it is necessary for solar companies to consider load balancing to guarantee stable outputs throughout the year (assuming that we want to minimize the use of base load from burning fossil fuels). It is, therefore, interesting to also take a look at the outputs across 12 months of a year. Figure 7 suggests that a smaller tilt angle will produce peak power in the summer, whereas a larger tilt angle will produce peak power in early fall. If the demand of electricity in the summer is higher than that in the fall, it may be more lucrative to position solar panels at a lower tilt angle.